Insulator-pin.



No. 890,891. PATENTED JUNE 16, 1908. c. J. DORFP. INSULATOR PIN.

APPLICATION FILED NOV. 18, I907.

M287. Q EQ A i supporting structure in various ways.

UNITED STATES PATENT OFFICE.

CONRAD J. DORFF, OF CHICAGO, ILLINOIS,;ASSIGNOR TO FREDRIG GREEK, OF CHICAGO, ILLINOIS.

INSULATOR-PIN.

.To all whom it may concern:

nois, have invented certain new and useful Improvements in Insulator-Pins, of which the following is a s ecification.

This invention re ates to improved means for supporting insulators, and especially the glass insulators commonly employed for carrying electric wires, such glass insulators being attached to their supports by means of a screw-thread connection. Being formed by molding, the screw-threads of such insulators frequently vary considerably inform.

It is one of the objects of this invention to provide an insulator pin adapted to yield slightly to accommodate itself to insulators having variations in their screw-threads. Such yielding construction also allows for the different coefiicients of expansion of the materials of which the insulators and the pins are made.

The invention also relates to the general improvement of insulator pins as regards cost of manufacture, durability and efiiciency.

In the accompanying drawings, Figure 1 is a side elevation of a bracket comprising two insulator pins embodying the features of my invention. Fig. 2 is a section on line 2 2 of Fig. 1. Fig. 3is a section on line 3 3 of Fig. 1. Fig. 4 is a section on line 4 1 of Fig 1. Fig. 5 IS a plan view of the blank from which the screw portion of the insulator pin 1s formed.

The insulator pin may be attached tpha e embodiment selected for illustration consists of abracket 1 formed by bending a metal bar to provide an attaching portion 2 and two insulator su ports 3. In the present instance, said metal ar is a piece ofchannel iron of common form.

Upon each of the insulator supports 3 isplaced a device forming a screw upon which the insulator a. is adapted to be turned. Said device, as herein shown, is made of an integral piece of sheet metal, the blank havlng substantially the form indicated in Fi 5. Each of'the portions 4 of said blank lsof sufficient width to be formed into substan tially a semicylindrical section, in which are pressed grooves constituting part of the screw-threads for the insulator pin. The part ofthe blank which connects the portions Specification of Letters Patent.

, Application filed November 18, 1907.

Patented June 16, 1908.

Serial No. 402,679.

4 is bent to provide a portion 5 by means of which the screw device is attached to the insulator support 3, the screw-threaded portions 4 being connected to the attaching portion 5 by the short arms 6. In the resent embodiment, the portion 5 is SGCUI'6( to the insulator support by cutting a shallow recess 7 in the end of the su port, placing the attaching portion 5 in said recess, and riveting the opposite walls 8 of said recess over upon said attaching portion, as indicated in Figs. 2 and 4. v

The screw portions 4 are held from rotation or lateral displacement, while free toyield toward and away. from each other, by means comprising, in this instance, a lug 9 integral with one of said screw ortions and bent to extend at a right ang e therewith, said lug having a reduced end 10 lying loosely within an o ening 11 in the insulator support. The s oulders 12 on said lug limit the inward movement of the screw portion to which said lug is attached. The opposite screw portion is provided with a lug 13 bent at a right angle with said screw portion and lying between the flanges of the channel bar.

The screw device is preferably made tapering as shown, and is attached to the insulator support 3 by its upper smaller end. The device is given its tapering form by pro erly proportioning the relative len ths o the parts 5 6 6 and the parts 9 13. The portions 4 also are preferably formed with two oppoeii te converging side edges, as indicated in When the glass insulator a is screwed u on the insulator pin, the screw portions 4 yield to accommodate themselves to any irregularities in the screw-threads of said insulator. Being resilient and slightly compressed when the insulator is screwed home, said screw portions also hold the insulator securely 1n place. When temperature changes cause contraction or expansion of the insulator and its su port, the spring portions4. yield to prevent breakageand to retain a firm iold upon the insulator..

It is obvious that various changes may be inade in the embodiment herein shown without departing from my invention. 1, therefore, do not limit myself to the precise details herein set forth.

I claim as my invention:

1. An insulator pin comprising a support ing member of channel form; two screw-sections having an attaching portion secured to tending at an angle therewith, said last mentioned lug having a reduced end lying within an 0 ening in said supporting member; and shoulders on the last mentioned lu 2. An integral sheet metal blanr for the screw portion of an insulator pin consisting of two parts adapted to form substantially semicylindrical screw-sections; an interme diate portion connecting said first mentioned parts; and a lug on each of said first mentioned parts.

3. An insulator pin comprising a supporting member; and two tapering screw sections yieldin ly attached to said supporting member at the smaller end of said sections.

4. An insulator pin comprising a supporting member having a recess in one end; two screw-sections having an intermediate connecting portion lying within said recess, the

walls of said recess being riveted to hold said intermediate connecting portion in place; and means at the opposite ends of said screw sections adapted to engage said supporting member to prevent rotational displacement of said sections.

5. An insulator pin comprising a supporting member in channel form; two screw sections yieldingly attached to said supporting member at one end; a lug on one of said screw sections lying between the flanges of said supporting member; and a lug on the other section lying within an opening in said supporting member. f

6. An insulator pin comprising a supporting member and two screw-sections yieldingly attached to said supporting member at their upper ends; and means at the lower ends of said screw sections engaging said supporting member for preventing displacement of said screw sections.

CONRAD J. DORFF.

Witnesses:

C. P. PARKER, GEORGE L. OHINDAHL. 

